A recent article that appeared online at the LA Times website suggests that great white sharks (Carcharodon carcharias) and giant squid (species from the Architeuthis genus) might “battle” it out in the depths of the Pacific. The theory, which other media outlets are running with as if it were scientifically proven, seems entirely based on research of migratory patterns of white sharks being conducted by Michael Domeier.
The research has revealed that migratory patterns of the white sharks take them to an area of the Pacific where Domeier’s research team found “barely any fish or other prey that the sharks might be eating,” aside from the presence of “purple and neon flying squids” and sperm whales. Sperm whales have been documented feeding on giant squid and, according to the LA Times article, are known to feed in spawning areas of large squid. The article also notes that the team found the carcass of a giant squid that appeared to have been chewed on, “perhaps by various predators.”
To sum the theory up, it is based merely on the simlutaneous presence of great white sharks, sperm whales, and squid in the same geographic area, coupled with a lack of understanding of why the white sharks are traveling to this particular area. There is no documented observation of white sharks and giant squid doing “battle.” While it’s not an impossibility that a white shark might feed on a giant squid, there really isn’t much to substantiate that it happens, aside from speculation.
My biggest doubt about this theory is based on the lack of any reported documentation of great white sharks bearing the tell-tale markings of defensive injuries caused by giant squid. Sperm whales have been known to be scarred with “sucker marks” from giant squid, yet there does not appear to be any documentation of these types of wounds on great white sharks. The white sharks that Domeier has been tracking were tagged at Isla de Guadalupe and the Farallon Islands, so these are sharks that get quite a bit of attention from researchers and underwater photographers/videographers, so it seems unlikely that such wounds/scars would go unnoticed. In fact, the markings and scars on the white sharks at Guadalupe and the Farallons are often documented and used to identify specific sharks.
The fact that a giant squid carcass was found with bite marks doesn’t necessarily support the white shark versus giant squid theory, either, especially considering that the LA Times article suggests the possibility that the wounds were from “various predators.” The article fails to mention what species were responsible for the bite wounds and whether the bites caused the death of the squid or were postmortem. Even postmortem bite wounds from a white shark wouldn’t substantiate a “battle” between the giant squid and a white shark. White sharks are known to scavenge when the opportunity presents itself, which might be a necessity based on the apparent lack of typical prey items, as noted by the research team. The article also reports that a known predator of giant squid (sperm whales) had been observed in the area, so it wouldn’t be a big surprise, if a sperm whale was feasting on a squid carcass.
Perhaps, next week an article about a great white sharks versus sperm whales theory will hit the press.